The present invention relates to beverage dispensing machines and, in particular, to a beverage cartridge and filter assembly for use in a beverage dispensing machine.
Single serving beverage cartridges are very popular because they provide a fresh tasting beverage quickly and conveniently. Beverages such as coffee are typically produced by beverage dispensing machines that use beverage cartridges holding beverage products.
Beverage cartridges typically comprise a sealed container having a top surface, a bottom surface and a filter. The filter subdivides the sealed container to provide an upper brewing chamber for housing a powdered or ground beverage and a lower chamber for receiving the filtered beverage. Beverage cartridges of the prior art are typically comprised of plastic or metal.
Prior art beverage cartridges are often expensive and difficult to manufacture. Reducing the number of processing steps required to form the cartridge typically results in lower item cost and reduces the manufacturing time. Stepped beverage cartridges, such as disclosed in European Patent Application No. 1101430, can be produced using a one-step vacuum forming process when they are manufactured from plastic. Such cartridges are difficult to manufacture when they are formed from a metal, such as aluminum, however.
Installing a filter in a beverage cartridge can be time consuming as several mounting steps are typically required. The heat sealing techniques that are currently employed to fix a filter in a cartridge, have been known to damage the beverage cartridge because the amount of working space inside the cartridge is limited. Some of these production faults are not discovered until the beverage cartridge has reached the consumer.
The type of filter used in a beverage cartridge has significant impact on the quality of the beverage product produced. Paper filters produce a high quality beverage. These filters, however, lack wet strength and can remove too much of the essential coffee oils and flavour. Metal filters, on the other hand, provide sufficient strength. Metal filters, however, allow higher levels of coffee oils to pass through into the brewed beverage. The high levels of produce a different taste in the coffee that is often undesirable. As will be appreciated, a filter is desired that has sufficient dry and wet strength to withstand the high pressures and temperatures associated with brewing but not produce a bitter tasting brewed beverage, as some synthetic filter media are known to do.
It is therefore an object of the present invention to provide a beverage cartridge and filter assembly that obviates or mitigates at least one of the above disadvantages.
According to one aspect of the present invention, there is provided a laminated filter assembly for subdividing a beverage cartridge to form a brewing chamber. The laminated filter assembly includes a first filter element having a first edge portion, the first filter element being comprised of a first material, a second filter element having a second edge portion, the second filter element being comprised of a second material, the second material differing from the first material. A seal is provided between the first edge portion and the second edge portion. The second filter element has a higher wet strength than the first filter element and the second filter element is located downstream of the first filter element.
According to another aspect of the present invention, there is provided a beverage cartridge comprising a container having a sidewall extending from a first surface and a lip provided at an open end of the container, a cover coupled to the lip of the container to cover the open end and seal the container, a sloped step formed in the sidewall, a filter coupled to the sloped step, the filter subdividing the container to form a brewing chamber and a beverage receiving chamber, and a beverage powder contained in the brewing chamber. The container is pierceable to allow injection of liquid into the brewing chamber and to allow prepared beverage to be extracted from the container.
According to another aspect of the present invention, there is provided a beverage cartridge including a container having a sidewall extending from a first surface and a lip provided at an open end of the container. A cover is coupled to the lip of the container to cover the open end and seal the container. A step is formed in the sidewall and a laminated filter structure is coupled to the step, the laminated filter structure subdividing the container to form a brewing chamber and a beverage receiving chamber. A beverage powder is contained in the brewing chamber. The laminated filter structure has a first filter element with a first edge portion, a second filter element with a second edge portion. A seal is provided between the first edge portion and the second edge portion. The second filter element is of a different material than the first filter element. The second filter element has a higher wet strength than the first filter element and the second filter element is located downstream of the first filter element. The container is pierceable to allow injection of liquid into the brewing chamber and to allow prepared beverage to be extracted from the container.
It is an advantage of an aspect of the present invention that a filter assembly is provided that has sufficient strength to withstand high pressures.
In another aspect, the sloped step allows the filter to be fused thereto more quickly and efficiently. The present invention provides a further advantage in that the stepped beverage cartridge can be manufactured by a single processing step regardless of the type of material that it is comprised of.